Mayor Thomas M. Menino on Thursday vetoed the City Council’s controversial plan for redrawing the nine council districts, arguing that the map diluted the influence of African-American, Hispanic, and Asian voters.
In a letter to the council, which approved a redistricting plan on a 7-6 vote after months of wrangling, Menino singled out District 4 as a source “of particular concern.” In that district, which spans parts of Dorchester and Mattapan, voters of color would constitute 95 percent of the electorate.
“My central objection is my concern that the plan concentrates our many citizens of color into too few districts,” Menino wrote, “and in doing so may limit their equal opportunity to elect candidates of their choice.”
The mayor’s veto means that the City Council, sharply divided on redistricting, will either have to muster a super-majority to override Menino or draft a new map.
A coalition of groups representing Boston’s minority populations had threatened to sue the city over the council-approved redistricting.
At last month’s hearing to vote on the map, Councilors Ayanna Pressley of Dorchester, Tito Jackson of Roxbury, and Charles C. Yancey of Dorchester delivered impassioned speeches arguing for more time to review and retool the map. They said the plan would limit the voting power of residents of color by concentrating African-Americans, Hispanics, and Asians in a small number of districts while excluding them from other districts.
Menino in his letter invoked a similar assessment.
“Though the task is not to guarantee the election of minority representatives, a plan should reasonably provide equal opportunities for protected groups to elect their candidates of choice,” Menino said.
The prime architect of the council’s redistricting proposal, Councilor Bill Linehan, expressed disappointment about Menino’s veto. Just as he acknowledged when the council voted two weeks ago, Linehan said Thursday the plan was not perfect but represented compromises between a series of proposals.
Linehan said he feared a consensus might never be reached. He said he had been confident the plan could have withstood a court challenge.
“It’s unfortunate that we spent 16 months working on this,” said Linehan, chairman of the Redistricting Committee. “A sleight of pen from the mayor sends us back to square one.”
District 4, he said, has long been a swath of the city composed mostly of people of color. Adjacent neighborhoods also have significant blocs of African-American and Hispanic voters, he said, making it almost impossible to drastically change the district’s demographics unless the council completely overhauls the current map.
“There’s very little wiggle room if you’re trying to move the population without throwing the whole thing up in the air and starting from scratch,” Linehan said.
In a statement Thursday, Pressley said she was pleased to have another opportunity to work on the map.
“We know the diversity of this city is only growing,” Pressley wrote. “Our final map needs to go farther to increase equitable representation, voice, power, and influence in city elections.”
It will take nine votes from city councilors to overrule the mayor’s veto. The 7-6 vote was unusual for the City Council, which often moves in lockstep. The council’s four members of color voted against the proposal.
The process of redrawing Boston’s nine districts is triggered by the US census each decade, part of an effort to ensure that the districts reflect shifts in population and include a comparable number of voters.
City Council President Stephen J. Murphy voted for the proposed redistricting plan but vowed to work with the mayor to reach a solution.
“We are encouraged by the spirit of cooperation that the mayor and his team offered and look forward to moving this issue toward a resolution that works for all,” Murphy said.
In addition to Linehan and Murphy, votes in favor of the redistricting map came from Councilors Frank Baker of Dorchester, Mark Ciommo of Brighton, Robert Consalvo of Hyde Park, Salvatore LaMattina of East Boston, and Matt O’Malley of Jamaica Plain.
Joining Pressley, Yancey, and Jackson in dissenting were John R. Connolly of West Roxbury, Felix G. Arroyo of Jamaica Plain, and Michael P. Ross of Mission Hill.
The coalition, representing a range of the city’s minority communities promising to sue the city, expressed satisfaction with Menino’s veto.
“Councilor Linehan’s map was ill-conceived, and I’m glad the mayor took the rational step of allowing the process to continue,” said Sean Daughtry, political action chairman for the Boston chapter of the National Association for the Advancement of Colored People.
Critics of the council’s plan had taken particular issue with District 2, which includes much of South Boston along with parts of the South End and Chinatown. That district — represented by Linehan, who nearly lost his reelection bid last year to a candidate from Chinatown — would have been made up of 32 percent of people of color, the lowest percentage in the city. Instead, critics said, it should come closer to reflecting the 53 percent of the city composed of African-Americans, Hispanics, and Asians.
Alejandra St. Guillen, executive director of Oiste, a statewide Latino civic organization, said she was disappointed Menino’s letter did not give an explicit nod to District 2. But she said she was pleased the mayor has offered another chance for city councilors to get it right.
“It was unfortunate the votes really fell along racial lines,” St. Guillen said. “Boston is a better city than that, and the council can do better.”Martine Powers can be reached at firstname.lastname@example.org. Follow her on Twitter @martinepowers.